Black Americans are three times as likely as their White counterparts to have kidney failure, yet many have waited longer for kidney transplants largely because of a race-based formula for calculating the stage of their disease.

Although a series of timed blood tests produces the most accurate measure of kidney function—the glomerular filtration rate (GFR)—a single blood test combined with a mathematical calculation is the most common way of measuring whether kidneys effectively filter the blood. This simpler test, the estimated GFR (eGFR), measures the presence of creatinine in the blood. The amount of creatinine is compared with amounts found in a reference population tested using the more cumbersome method and then adjusted to account for age, gender, and racial differences.

Because Black individuals were found to have higher creatinine levels in some research populations when the eGFR test equations were developed in the late 1990s, a decision was made to raise all Black patients' eGFR by 16% in evaluating their disease. Recent research suggests this increase systematically made their health appear better than it likely was, delaying more aggressive treatment of their kidney disease and their eligibility for transplants.

In response, the Organ Procurement and Transplantation Network (OPTN), which oversees organ procurement and transplantation for the U.S. Department of Health and Human Services, adopted two policy changes. In June 2022, the OPTN approved a measure to require hospitals to stop using race when calculating a patient's kidney function. In December, the board went a step further, instructing kidney transplant programs to identify Black candidates who qualified for a kidney transplant based on a race-inclusive eGFR calculation and to determine whether a race-neutral eGFR calculation would have qualified them earlier. If so, the OPTN requires transplant programs to apply to have the patient's waiting time for an organ adjusted. Programs have one year to comply. Researchers estimate 85,000 Black adults could benefit from the policy.

A prospective cohort study by Zelnick and colleagues in the January 2021 JAMA Network Open compared the eGFR of 1,658 Black participants enrolled in the Chronic Renal Insufficiency Cohort Study with their iGFR, a direct measure of kidney function considered the gold standard for determining the bias of other estimates. The authors found participants would have reached the threshold for transplant eligibility 1.9 years earlier on average had their kidney function been calculated without the race-based adjustment.

Commenting on the opportunity for Black kidney patients to receive correct waiting times, Jerry McCauley, president of the OPTN board, said, “This action underscores our commitment to equity in access to transplantation for all candidates. . . . We are acting along with kidney transplant programs nationwide to ensure that any candidates known to have been disadvantaged by a race-inclusive GFR calculation will receive all the waiting time credit for which they qualify.”—Nicole Fauteux